This is exactly what happens to me on my PS4. It seems to be like a shift in the controls or something and suddenly I am unable to select a node or anything on my ship. This basically happens to me almost every flight, especially if they are anywhere outside of kerbin's gravity (but it has also happened in kerbins orbit as well).
What seems to happen is when I'm trying to adjust a manuever, I hold down X when moving the retrograde or anything else, and when the mouse seems to line up with an orbit line as well and I release X it accidentally selects the orbit line and prompts you to set a node or warp time. I always ignore these of course but when I seem to back out quickly and spam O out of frustration that's when my ability to place a node or even select ANYTHING disappears and you can really see a shift in the control system like something changed. It's as if too much happens at one time for ksp to keep up with it.
Loading a quick save never seems to work to fix it and I am yet to find a solution without quitting the game. If you check the bug page this isn't even marked as a bug. So if anyone knows anyone with access to that, please report it because it can ruin career modes and make the game almost unplayable.